1. Field of the Invention
The present invention relates generally to the field of medical devices, and more particularly, to a graft to re-line a debulked vessel.
2. Description of Related Art
Arterial stenosis is a disease of the artery wherein a portion of the vessel becomes occluded, primarily with plaque (atheroma) containing cholesterol, lipid material, macrophages and proliferating smooth muscle cells, consequently restricting blood flow and causing further complications. Traditionally, arterial stenosis has been treated by surgical construction of a bypass channel to connect healthy parts of the vessel around the atheroma. While the bypass method may produce good results, a major disadvantage is the invasiveness of the surgery because the procedure requires general anesthesia and a substantial post-surgical healing period.
Another, less invasive method of treatment includes balloon catheter angioplasty, where a balloon catheter is inserted into the diseased portion of the vessel and inflated, pushing the atheroma outward and opening the vessel. While balloon catheter angioplasty is much less invasive than bypass surgery, it does not enjoy similar success rates due to frequent restenosis of the vessel. To overcome this problem, stents and other similar endoluminal devices may be inserted to keep the vessel open following angioplasty. Cellular infiltration through the stents"" mesh-like structure makes the use of bare stents less than optimal, particularly in longer ( greater than 5 cm) legions. Consequently, the stent may be covered with a biocompatible material such as polytetrafluoroethylene (PTFE) to prevent cellular infiltration.
Endarterectomy is a method for treating occluded portions of a vessel where the atheroma is surgically removed, along with the inner two layers (intima and media) of the three-layered artery. Following the endarterectomy, only the adventitia layer remains, thus the vessel can be prone to cellular accumulation and thrombosis.
Artherectomy is a method for treating occluded blood vessels where a mechanical device is inserted into the vessel, removing atheroma by cutting or grinding the plaque and creating an open channel. Similar to endarterectomy, this procedure can trigger a cellular response that leads to thrombosis and/or restenosis of the vessel.
Another term for endarterectomy and artherectomy is xe2x80x9cdebulking.xe2x80x9d Debulking is simply the removal of atheroma, plaque and other tissue to restore blood flow in a vessel. To prevent the cellular response that leads to thrombosis and/or restenosis following a debulking procedure, the vessel can be re-lined with PTFE or other biocompatible materials.
Many delivery systems have been used for introducing stents, grafts, and other endoluminal devices into bodily vessels with minimum invasiveness. One problem with a number of these systems, however, is that they require multiple components and procedural steps to deliver and deploy the device against the vessel wall. In addition, grafts and -other endoluminal devices used to currently re-line vessels are not optimal due to problems with effectively anchoring the device within the vessel.
The present invention overcomes these stated drawbacks by providing a simple delivery system and device to re-line a vessel following debulking.
The present invention is directed to a delivery system and device for re-lining blood vessels. In particular, following debulking procedures, a graft containing a stent or other fixation device is deployed slightly distal to the debulked section of the vessel. A small balloon on the shaft of the delivery catheter is inflated to ensure good opposition of the graft to the vessel wall. Next, the delivery system is removed through the newly implanted graft, which is sutured proximally to the debulked vessel.
It is an object of this invention to provide an endoluminal vascular graft device to re-line a debulked vessel as a less invasive alternative to traditional surgical bypass.
It is another object of this invention to provide an endoluminal vascular graft device that has a minimal profile when loaded into an insertion system, can be seen with fluoroscopic imaging and can be deployed quickly and easily.
It is yet another object of this invention to provide a delivery system to introduce the endoluminal vascular graft device quickly, easily and effectively within the debulked vessel.
These and additional objects are accomplished by delivering a graft with an attached stent or other support structure to a debulked vessel. The replacement lining is delivered to the desired site by, using a delivery system, including an atraumatic tip to house the stent, a sliding hub attached to the graft lining material, and an inner shaft connected to the tip.
To prepare the replacement lining for delivery, the distal stent is bonded, attached or encapsulated to the graft material. The graft material can either be supported, unsupported, or a combination of the two to resist compression. The distal portion is compressed into the atraumatic tip for delivery to the desired site within the treated vessel. Ideally, a self-expanding stent is used for this purpose so that the deployment of the stent occurs quickly, as soon as it is released from the atraumatic tip, thus ensuring that the stent can be deployed at the pre-selected location without migration in either direction within the vessel.
The atraumatic tip is connected to an inner shaft that extends through the compressed stent and graft material to the proximal end of the delivery device. The connection between the tip and the shaft allows the device to be maneuvered as it is being inserted into the vessel. Optionally coupled to the shaft, proximal to the loaded stent, is a balloon that is positioned to be inside of the stent after the stent is removed from the atraumatic tip. Once the stent is removed from the atraumatic tip and expands to come into contact with the vessel wall, the balloon can be inflated to ensure a good fit to the vessel wall. A sliding hub is attached to the proximal end of the graft lining material so that the distal stent can be pulled out of the atraumatic tip. After the delivery system is removed from the vessel and the graft lining material is pulled taut, the sliding hub is cut off of the graft lining material and the lining material is sutured to the treated vessel.
A more complete understanding of the endoluminally placed vascular graft and delivery system will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of the preferred embodiment; Reference will be made to the appended sheets of drawings, which will first be described briefly.